Art of testing materials of hygroscopic nature



Get. 5 1926.

- 1,502,213 C. H. ROBBINS I ART OF TESTING MATERIALS OF HYGROSCOPIC NATURE 2 Shets-Sheet 1 Filed May 16, 1919 flvekzarrorney Oct.5,1926. v v J 1,602,213

- c. H. ROBE-INS ART 915 TESTING MATERIALS 0F HYGROSCOPIC NATURE Filed May 16, 1919 2 Sheets-Sheet 2 Patented Oct. 5, 1926.

' uNrrsu S AT S PATENT o s.

. CHARLES H. ROBBINS, OF'NEW BEDFORD, MASSACHUSETTS, ASSIGNOR T MANOMET MILLS, OF NEW IBEDFORD, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

ART'OF TESTING MATERIALS 0]? HYG ROSOOPIC NATURE.

Application filed my 16, 1919. Serial No. 297,658.

The invention has for one of its main objects to perform the testing of fibers, yarns and fabrics composed thereof, and other hygroscopic materials and products,

upon a basis that will permit true and acatio'n to ascertain the relative proportioncurate determination of. strength, actual fiber content or the like, or other qualities, properties, or factors, that are affected or influenced by the moisture-content of the material or product while under oing a" test, without the uncertainties an errors that occur when the moisture-content is not accurately known. Also, without it being necessary to correlate what is known as regain with either temperature, relatlve humidity, or barometric conditions, and without it being necessary to maintain a constant temperature. Also, without it being necessary to possess and refer to prepared regain tables and charts, and without any other calculations than the very simplest.

.The invention, accordingly, comprises an improvement in the art of testing materials and products of hygroscopic'nature.

The tests themselves may be any of those which usually are performed incidentally to sale transactions and to manufacturing operations. For example, a test may consist simply in a weighing operation, in order. to ascertain the relative proportion of water in a given quantity of cotton or otherfiber. Or it may consist in a weighing operof moisture content in a lap, sliver, roving, yarn, etc., in process of manufacture. Or it may consist in a breaking test for the ascertainment of the strength of a yarn or a piece of cloth.

The drawings show one means of carrying into effect the said improvement in the art J of testing materials.

. general circulation of air.

other words it comprises the step of giving an exact predetermined moisture-content to the test-sample, by adding to or taking from 1ts moisture-content, so that the strength, actual weight of fiber, etc., admit of being determined with practical certainty. Since thestrength and weight of fibrous materials, for instance, both vary with the moisturecontent, the true strength, and the true quantitative determination cannot be arrived at with certainty and correctly when the moisture-content has not been reliably ascertained.

In conformity with the improvement in the art, the said quantitative standardization of the test-sample is effected by exposing the latter in an atmosphere that is humidified, as by means of a humidifier, I, under control of a hygrometer of which the determinative element or moisture-sensitive agent, otherwise control-element consists essentially in a quantity 2, of known bonedry weight, of material'of. the same kind as the sample, exposed to such atmosphere. This standardization is effected in a closed cabinet A, in order that the atmosphere may remain unchanging in the sense of remain ing constant and without the changes of conditions which would result in case of The said control-element, i. e., determinative element or moisture-sensitive agent .2 is shown as a piece of cloth, termed by me a shirt and usually'composed of knit goods,

suspendedby means of a suitable hook or hanger 31 and wire frame 3 from a weight 4 hung upon the short arm of a scale-beam 5 pivotally mounted upon a support 6. Weight 4 is emplo ed as a counterbalance for the long arm 0 the scale-beam, and the hook 71 that is applied to the free extremity of such arm. Exactness'in the counterbalancing of the said long arm and hook is provided for by means of one or more small weights 41, which are mounted upon the extremi ty of the short arm of'the scale-beam with capacity for adjustment toward and from the beam-fulcrum. With the long arm of the scale-beam are combined the weights 7 and 10, the first-mentioned thereof being a disk or the like that is hung upon hook 71 depending from the free extremity of the said long arm, and the other thereof being asmall 'slide that is mounted upon such arm with capacity to be shifted along said arm acter and construction.

toward and from the scale-beam fulcrum.

The weight 7 serves, as one of its functions, to balance the weight of hanger 31 and the bone-dry weight of the shirt, and the two weights (7 and-10) serve individually or conjointly, asthe case may be, to weigh-the percentage of moisture absorbed by the shirt. An electric circuit embracing the controlling connections for the humidifier has terminals constituted by a mercury cup 8 mounted adjacent the scale-beam, and a wire or point 9 carried by the scale-beam and adapted to dip into the said cup. When the wire or point is separated from the mercury, the humidifier is inactive and no humidity is supplied to the atmosphere of the cabinet;

-when the wire or point touches or enters the supplies humidity.

A- humidifier of conventional form is represented at lin Figs. 1 and 3 of the drawings. It may be of any approved char- The valve mechanism thereof, as represented in Figs. 1 and 2, is of ordinary character, comprising a balanced valve a. ificonnection with the water supply-pipe 1 leading to the humidifier, a valve 12 which controls the airpressure coming through the air-supply pipe 0 by means of which the said balanced valve is operated in opposition to its actuating spring d, and a solenoid 6 having its core joined by a connection 7 with the sa d air-valve. The wiring g, h, of the electrlc circuit governed by the make and break device-constituted by the mercury cup 8 and wire or point 9 is combined with that of the solenoid, so that the latter is controlled by means of the said make and break device; in turn the solenoid controls the working of the humidifier in fwell-known' manner which will be obvious.

In the cabinet equipped with the abovedescribed apparatus, including the shirt, the test-sample is placed, the weight-load carried by the long arm of the scale-beam be-.

ing" varied or adjusted according to the amount of humidity required in the test sample for its quantitative standardizing. Usually, primarily, such weight-load overbalances the scale-beam so that the wire or point 9 dips into the mercury, closin the circuit and thereby rendering the humi ifier active so as to supply humidity to the atmosphere within the cabinet. tinues until the shirt has absorbed suflicient moisture to balance the scale-beam and withdraw 'the wire or point from the mercury, whereby the circuit will be broken and the humidifier will become inactive. Any subsequent decrease in the humidity of the atmosphere within the cabinet, and resultpensated for through the humidifier bein This con-- consequently the moisture-content of the atmosphere will be maintained at a constant amount. After the test-sample has remained in the thus regulated atmosphere sufficiently long to ensure that its moisture-content has conformed to the state of humidity of the said atmosphere, the test or tests is or are performed in the said atmosphere upon the thus-standardized test-sample.

By reason of using a shirt? of the same kind of material as the test-sample, of cotton in case thesainple is of cotton, silk in the case of silk, wool in the case of wool, etc, practically identical amounts of moisture will be taken up by both the shirt and the sample. Consequently, by having the scale-beam properly graduated, and by making obvious adjustments of the scaleweight thereon, the test-sample can be given any desired weight of regain, i. e., per.- centage of moisture-content for the testing.

In practice, the shirt employed has been of 1000 grains, bone-dry weight. The (detachably applied) weight has been proportioned to exactly balance the said 1000 grains weight of the shirt, plus the desired per cent of acquired moisture. The parts and the sliding scaleweight 10 have been so proportioned that when the sliding scaleweight 10 is at the outer end of the gradua tions it will balance 10 grains. The ratio being 10: 1000, when at such end the sliding scale-weight will balance one per cent of the bone-dry weight of the shirt. The scalebeam has been graduated for tenths and hundredths, and hence the graduations indicate tenths and hundredths of one per cent of the bone-dry weighttof the shirt. In keeping with such graduations, the scaleis constructed and calibrated to be sensible to a variation in weight of one-tenth of one grain. Therefore, in virtue of the foregoing ratio, the sliding scale-weight 10 will indicate by direct reading (self-computing) differences or variations of one one-hun- 11 dredth of one per cent of the bone-dry weight of the shirt hung on the load arm of the scale, or of any number of hundredths or tenths of one per cent up to one per cent. Thus, according to the present demonstration'of the principles of the invention, adjustment of the slidmg weight 10 enables any desired fraction of one per cent of the moisture-content in the shirt to be Wei hed. The two weights 7 and 10 enable t e desired perautomatically rendered active again, an a humidifying agency controlled by variations in the weight of moisture absorbed by a control-element consisting of a known bone-dry weight of material of the same kind as that to be tested, said degree being attained and maintained through adjustment of the 1point at which the humidifying agency shal become operative or in0perative, (b) quantitatively standardizing by addition or subtraction as the case may be under such control the moisture content 0% a test-sample of the material to be tested, by subjection to the said atmosphere, and (a) performing within the said atmosphere the test or tests upon the moisture-contentstandardized test-sample.

2. The art of standardizing for testing for strength or other properties that are influenced by humidity materials of hygroscopic nature, which consists in (a) pro 110- ment of the ing in an otherwise unchanging atmosphere a predetermined degree of humldity through a humidifying a ency controlled by variations in the weig t of moisture absorbed by a control-element consistin of a known bone-dry weight of materlal of the same kind as that to be tested, said de ree being attained and maintained throug ad'ustoint at which the humi ifying agency s all become 0 erative or inoperative, as the case may e, under such control, and (b) quantitatively standardizing the moisture content of a test-sample of the material to be tested by subjection to the said atmosphere.

In testimony whereof I afiix my signature.

CHARLES H. ROBBINS. 

